DesignSoft
December 18, 2017, 06:39:22 AM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
News: Welcome to TINACloud, the cloud based version of TINA, running in your browser without any installation and anywhere in the world. For limited time, now you can get it for free if you purchase a new license or upgrade to v10 version of TINA at www.tinacloud.com.  With this great extension you can present or modify your designs wherever you are in the world and even while travelling.

We are eager to hear from you any comments and feedback.
 
 
   Home   Help Search Login Register  
Pages: [1]
  Print  
Author Topic: Sum of powers wrong  (Read 560 times)
Panometric
Newbie
*
Posts: 4


View Profile
« on: May 17, 2017, 02:12:58 PM »

Whats wrong here? The circuit is dissipating 1W into the speaker, yet the total consumption of the power supplies is less than 1 watt.  Interestingly I get the same consumption on the supplies whether doing AC or DC analysis. Even adding all AC and DC together is still < 1 Watt. Hopefully you will tell me I invented a perpetual energy machine ;-)
« Last Edit: May 17, 2017, 02:24:05 PM by Panometric » Logged
CDRIVE
Full Member
***
Posts: 168


South Florida USA


View Profile
« Reply #1 on: May 17, 2017, 05:18:48 PM »

In DC (Interactive) the speaker should dissipate 0W and that's exactly what I get in my Tina11.

Chris
Logged

___________________________________________
Working with electricity can be dangerous. Any information that I post, including schematics and or code are intended for educational purposes only. No warranty of circuit or code suitability is expressed or implied. Proceed at your own risk.
CDRIVE
Full Member
***
Posts: 168


South Florida USA


View Profile
« Reply #2 on: May 17, 2017, 05:40:21 PM »

Here's what I did. While running in Interactive Transit mode take a screen shot and view it in Paint. . I rely on AC interactive mode for very few simulations.

Chris

Logged

___________________________________________
Working with electricity can be dangerous. Any information that I post, including schematics and or code are intended for educational purposes only. No warranty of circuit or code suitability is expressed or implied. Proceed at your own risk.
Panometric
Newbie
*
Posts: 4


View Profile
« Reply #3 on: May 17, 2017, 06:00:57 PM »

Thanks for the tip Chris.

Ahh, I see that the probed figure is for t0, the transient analysis shows the peak power alternating form the expected supply. That is very misleading.
So I am probably analyzing wrong.  How do I get peak and average power over at least one waveform cycle?
Logged
CDRIVE
Full Member
***
Posts: 168


South Florida USA


View Profile
« Reply #4 on: May 17, 2017, 07:28:09 PM »

Well that wasn't what I meant by a Screen Shot (Print Screen) in my last post. I was referring to Transit (Interactive Mode).

What you have in your last post is the most accurate method of simulating. Your image is of Transit 'Plot Mode'. All those waveforms are peak values because they're instantaneous values like a scope measures. You can convert Peak values to RMS by multiplying the value at any point by 0.707.

BTW, when you punch in voltage levels on Tina AC Voltage and Current sources the value you enter is also a Peak value. So if you ever find yourself simulating a power transformer (Mains Power) and your powering it with a AC Voltage Source/Gen you have to keep that in mind.
For example: Setting up a Tina Voltage Gen for 120VAC Mains Power would require the Sinewave voltage to be set at 120V * 1.4143. More precise methods can be   found on the net. Just Google "RMS to Peak Converter".

Cheers,
Chris
« Last Edit: May 17, 2017, 07:30:58 PM by CDRIVE » Logged

___________________________________________
Working with electricity can be dangerous. Any information that I post, including schematics and or code are intended for educational purposes only. No warranty of circuit or code suitability is expressed or implied. Proceed at your own risk.
etl17
Newbie
*
Posts: 26


View Profile
« Reply #5 on: May 18, 2017, 09:49:19 AM »

It seems that you have two additional sources of energy that you are not accounting for.
The signal generator in the input, as well as, the additional 4.2V source.
Logged
Panometric
Newbie
*
Posts: 4


View Profile
« Reply #6 on: May 18, 2017, 12:52:32 PM »

I found my answer, for the record: It is not the unaccounted for input signal or enable bias, those are both very high impedance, so inconsequential. And I don't have the interactive transient option since this is Tina-TI.

The issue is that the analyzer is instantaneous and always starts at T0. To get the average power I had to:
1. Make the battery non-ideal by adding some internal resistance.
2. Put a large cap between the meter and the circuit to integrate the power.
3. Use the power from the transient chart sometime after T0 where it levels off. The power printed on the schematic is always wrong.

Now I see each supply has an average consumption of 1W, so the circuit is about 50% efficient, that is what I expected.

If there was an easier way to just get that on the screen as part of the AC analysis,  it would be nice to know.
Logged
CDRIVE
Full Member
***
Posts: 168


South Florida USA


View Profile
« Reply #7 on: May 18, 2017, 03:46:04 PM »

I don't have Tina TI, so I don't know what AC Analysis options it provides. It will certainly be less than what Tina11 Classic DS provides. I do know that my version of AC Analysis provides the following..

Calculate Nodal Voltages
Table Of AC Results
AC Transfer Characteristic
Phasor Diagram
Time Function
Network Analysis

None of which is relevant to what you want to measure. That should be done in Transit Analysis.

Chris
Logged

___________________________________________
Working with electricity can be dangerous. Any information that I post, including schematics and or code are intended for educational purposes only. No warranty of circuit or code suitability is expressed or implied. Proceed at your own risk.
Pages: [1]
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.9 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!